Synthesis And Properties Of N-containing Ligand MOFs And Hollow ZnO@ZIF-8 Complex

Metal-organic frameworks materials(Metal-organic frameworks = MOFs),as crystalline porous material,are formed by the self-assembly of organic ligands and metal units.MOFs materials feature large specific surface area,high porosity,high structure and function.Therefore,the MOFs materials have attracted wide attention in the fields of gas adsorption and separation,fluorescence properties,electrochemical properties,chemical sensors and so on in recent years.The development of novel MOFs and its application are of great significance.The main achievements of this dissertation are as follows:1.Construction of two kind of new metal-organic frameworks based on single metal ion.HNU-20 is based on the semi rigid nitrogen containing ligands 5-(Bis-carboxymethyl-amino)-isophthalic acid(H4L1)and MnCl2 with the formula of[Mn3(L1)2(H2O)6]H2O.Through the analysis of the structure by X-ray diffraction,the structure of HNU-20 is based on a dinuclear Mn ion clusters and H4L1 ligands,forming a two-dimensional layered structure.The three-dimensional supramolecular structures is formed through the hydrogen bonds.HNU-21 is the based on semi rigid nitrogen containing ligands 5-Bis(3-carbonyIbenzyl)-aminoisophthalic acid(H4L2),5-ligand methyl tetrazolium(5-Methyl-1 H-tertazole=mtz)and Zn(OAc)2·2H2O under hydrothermal conditions with the formula of Zn2L2(mtz)2,The result shows that HNU-21 contains three-dimensional pore,and the solvent-accessible surface area is about 64.3%,When the Zn2+ and ligands are simplified,the overall structure can be refarded as 4-connected sod topology.Finally,the results show that HNU-21 has a good effect on selective recognition of Fe3+ ion,and detection line is 10-4mol/L.Furthermore,six kinds of explosives have been investigated,and the quenching effect toward 2,4-dinitrophenol is much significan,with the detection line of10-3mol/L.2.Two kind of metal-organic frameworks based on mix-metal ions.Througth the assembling of 5-Bis(3-carbonyIbenzyl)-aminoisophthalic acid(H4L2)with ZnC12 and LiNO3,under hydrothermal conditions,a compound ZnLi2L2(DMF)2(HNU-22)was successfully synthesized;When the Zn2+ was replace by Co2+,HNU-23was successful synthesis.The result showed that HNU-22 and HNU-23 are isomorphic,the structure of each metal cluster is connected with the 8 ligands,while each ligand links 4 metal clusters,.If metal clusters and ligands respectively as the node,the whole frame can be simplified as the topology of 4,8-connection,and the topological type is flu with the symbol of {412.612.84}{46}2.The fluorescence properties of HNU-22 are finally investigated.The results show that HNU-22 has a good effect on recognition of metal Fe3+,the detection line at 10-3mol/L mol/L,Moreover,the fluorescent respond of HNU-22 toward 2,4-dinitrophenol are also studied.HNU-22 shows good fluorescent recognition capability,with the detection line of 10-4mol/L.3.Study of synthesis and properties based on ZIF-8.Hollow ZnO@ZIF-8 composites were successfully synthesized on the basis of hollow ZnO as the growth of ZIF-8.Themicrostructure and morphology of the obtained materials were characterized by scanning electron microscopy(SEM),transmission electron microscopy(TEM)and X-ray powder diffraction(XRD).The gas sensing properties were investigated.The results showed that the gas sensing of hollow ZnO@ZIF-8 microspheres were obviously improved compared with ZnO,and the effect of ZIF-8 loading on hollow ZnO microspheres was found to play an important role in improving the ethanol detection sensitivity.